rivt is an open source software project for writing and formatting engineering documents. Documents are produced in text, HTML or PDF, and are referred to as rivt docs. Docs are generated from rivt markup text files, referred to as rivt files.
A rivt file is a Python file (.py) that imports the rivtlib Python package and interprets rivt markup. A rivt file can publish docs in all formats and can be collated with other docs into a structured, linked rivt report. This site is an example of a rivt report.
An interface for finding public rivt files on GitHub is here.